Space Race update.

Da Vinci update.
Passages are used last (to take a good job if no housing is available with such a job elsewhere), as to minimize workplace performance reduction.
Specialized colonists should prioritize empty "basic support buildings" (such as groceries, dinners, ... but not infirmary which is specialized) more.

EarthSick and StressedOut colonists now behave like seniors until they get better and can work again (that is they avoid domes with much needed workforce and/or insufficient housing)

Fix dome colonists pop-up that could get stuck empty on screen.

- robust limit birth to perfect amount of nusery slots (powered off nurseries do not count)
- settings for Idiots changed, check your Mod Config settings :
Idiots CAN (from cannot) work : All, Specialized, Unspecialized, None
The setting should be updated but if not or unsure, scroll through them and choose the one you want.

Mod config bug fixed : user settings are applied by default without the need to change them each time you start a new map or load a game.

Added safeguard for the global variable for backward compatibility.

Solved possible issue with the global variable used for migration caching and current / new games.

Migration caching for precise migration and worker distribution.

Fix massive migrations that could occur when a lot of workers were doing jobs with a wrong specialization and a new matching workplace is built.